Effects of dietary fats on learning, pain threshold, thermoregulation and motor activity in rats: interaction with the length of feeding period

The effects of both a semisynthetic diet containing 20% fat from various sources (soybean oil, sunflower oil and lard) and a control diet on learning capacity, motor activity, pain threshold and thermoregulation were studied in rats which were fed on these diets for various lengths of feeding periods (1, 2, 3 and 4 weeks). Two weeks feeding period of soybean oil source induced an improvement in learning capacity, which was further enhanced by increasing the length of the feeding period. A 3-week feeding period was required to obtain an increase in the pain threshold, by which time the rats were also protected from d-amphetamine induced hypothermia. The analgesia induced by the diet is naloxone-dependent. None of the other diets, including the sunflower oil diet, which is richer in polyunsaturated fatty acids, differed from control diet. While the mode of action of this diet is still unknown, the effects of the soybean oil source diet cannot be attributed to nutritional factors such as changes in energy consumption or body weight.     

Habituation and transfer during sleep in cats.

In order to test the concept of "sleep learning", cats were exposed to habituation treatment of auditory stimuli during different stages of the sleep-waking cycle. While it was possible to demonstrate that habituation to an auditory stimulus can take place in paradoxical sleep (PS) and slow-wave sleep (SWS) as well as during periods of wakefulness, it was not always possible to demonstrate a transfer of habituation from the training period to other periods. A complete transfer of habituation occurred between the two sleep periods (PS and SWS); a partial transfer of habituation occurred between the waking period and both of the two sleep stages (PS and SWS), but only a minimal transfer of habituation was found between any one of the sleep stages and the waking period. When the cats were able to transfer the habituation, they also were able to discriminate between the habituating tone and a novel tone. The findings that only minimal transfer of habituation could occur between each of the sleep stages and the waking period do not lend support to the concept of "sleep learning".     

Plowing the atrium and growing thrombi: two cases of large atrial thrombi following ablative and surgical procedure for atrial fibrillation.

AIM: We present two patients with a large left atrial (LA) thrombus following invasive treatment for atrial fibrillation and inadequate anticoagulation. METHODS AND RESULTS: Case 1: A 30-year-old woman, with a one-year history of symptomatic paroxysmal atrial fibrillation resistant to medical therapy, underwent catheter ablation for atrial fibrillation. Three days after the procedure the patient presented with dizziness, fatigue, rapid atrial fibrillation with a sub-therapeutic INR. Transesophageal echocardiography (TEE) revealed a large LA thrombus. Case 2: A 59-year-old male, with severe mitral regurgitation and chronic atrial fibrillation, underwent mitral valve repair and Cox-Maze procedure. Three months later, while asymptomatic, a follow-up transthoracic echocardiography a large posterior LA thrombus was imaged. His INR was also sub-therapeutic. Both patients were treated by enhancing anticoagulation and close echocardiographic follow-up. So far both patients have remained asymptomatic two months following discharge. CONCLUSION: Large LA thrombi detected by transthoracic echocardiography are a rare complication of the Cox-Maze procedure and radio-frequency ablation for atrial fibrillation, which may occur even in patients with restored normal sinus rhythm receiving inadequate anticoagulation therapy.     

Utility of pulmonary hypertension for the prediction of heart failure following acute myocardial infarction

Pulmonary hypertension (PH) is usually perceived as a complication of established heart failure (HF) rather than as a predictor of HF or a marker of subclinical HF. PH may develop because of cardiac alterations that result in increased filling pressures after acute myocardial infarction (AMI). We hypothesized that PH might be a useful marker to predict the risk of HF after AMI. We studied 1,054 patients with AMI. Pulmonary artery systolic pressure (PASP) was estimated using echocardiography at the index admission and PH was defined as a PASP >35 mm Hg. The primary end point was readmission for HF at 1 year. PH was present in 471 patients (44.6%) and was strongly associated with age, decreased ejection fraction, advanced diastolic dysfunction, and moderate/severe mitral regurgitation (p <0.0001 for all comparisons). Area under the receiver operating characteristic curve was significantly higher for estimated PASP (0.74 ± 0.02) compared to other echocardiographic parameters (p = 0.02 to 0.0003). After adjustments for clinical and echocardiographic variables in a Cox model, PH was associated with a hazard ratio of 3.10 for HF (95% confidence interval 1.31 to 2.57, p <0.0001). After adding estimated PASP to a model containing clinical and echocardiographic risk factors, net reclassification improvement was 0.21 (95% confidence interval 0.11 to 0.31, p <0.0001). In conclusion, PASP integrates the severity of multiple hemodynamic determinants of increased left atrial pressures that lead to an increase in pulmonary venous pressure. In AMI, PH at the index admission is a useful marker in unmasking latent subclinical HF and predicting the development of overt HF.     

Programmable multiple pacing configurations help to overcome high left ventricular pacing thresholds and avoid phrenic nerve stimulation

BACKGROUND: High left ventricular pacing (LVP) thresholds and phrenic nerve stimulation (PNS) are common problems with cardiac resynchronization (CRT). Newer systems capable of multiple LVP configurations may help overcome these problems without the need for reoperation. METHODS: CRT systems capable of multiple LVP configurations (Guidant models H155 and H145) were implanted in 43 patients (study group). An additional 49 patients (control group) received CRT systems (Guidant, Medtronic, Biotronik, St. Jude Medical, various models) lacking this feature. RESULTS: Overall, acute high (> or =2.5 V/0.5 ms) LVP thresholds were encountered in 13 (30%) of the study group, and 25 (50%) of control group patients (P = 0.03). PNS was encountered in 5 (12%) of the study group and 12 (24%) of control group patients (P = 0.13). All cases of high LVP thresholds and PNS in the study group were managed by switching to a different LVP configuration, while high thresholds remained in control group patients, and PNS was managed by replacing the lead. The CS lead was successfully placed in a lateral branch in 95% of study group, compared to only 77% of control group patients (P = 0.004). CONCLUSIONS: Multiple LVP configurations were clinically useful in a significant number of patients undergoing CRT system implantation by helping to overcome high LVP thresholds and PNS, and by providing more flexibility in placing the LV lead.     

Prediction of survival: a comparison between two subjective health measures in an elderly population

A large amount of evidence shows that the subjective evaluation of health is a predictor of survival in many different populations. Subjective health (SH) is measured using different types of measures such as a general evaluation of health or a comparative evaluation of health. The aim of this study was to compare the prediction of survival by two measures of SH (a general measure and an age-related measure) and evaluate the association with other variables in an elderly population. The baseline survey was conducted during 1994, covering 1138 men and women aged over 70. The survival status was ascertained 7 years later. After adjustment for age, sex, education, marital status, perceived socioeconomic status and presence of diseases the two SH measures were found to be predictors of mortality, but only in men. In men, there was no significant difference between the two types of SH measures in their prediction of mortality. Also in men, when there was only one or no disease, being married had a protective effect compared with not being married when both types of SH measures were used. In elderly women, the association between the two types of SH and survival diminished after adjusting for the various variables. However, the general SH measure may be the preferable measure to use when needed. Education in women was associated with mortality only via the age-related SH measure.     

A locus for complicated hereditary spastic paraplegia maps to chromosome 1q24-q32

We updated the clinical features of a consanguineous Arab Israeli family, in which four of seven children were affected by spastic paraplegia complicated by skin pigmentary abnormalities. A genomewide linkage screen performed for the family identified a new locus (SPG23) for this form of hereditary spastic paraplegia, in an approximately 25cM region of chromosome 1q24-q32, with a peak logarithm of odds score of 3.05.     

The effects of DSIP on pain threshold during light and dark periods in rats are not naloxone-sensitive

The effects of Delta-Sleep-Induced Peptide (DSIP) were examined in rats kept at 12:12 light:dark schedule. The peak of the circadian pain threshold of saline-treated rats occurred at 10:00. Rats treated with 0.1 mg/kg, i.p. DSIP exhibited a significantly higher pain threshold level (as measured by hot plate) both in the light and dark periods. Prior to the treatment the peak was at 10:00. With treatment the peak shifted to 18:00. A dose of 1.0 mg/kg DSIP increased the pain threshold level only during the dark period. The analgesia induced by DSIP is insensitive to naloxone pretreatment.